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应用GW统计接触模型,建立了粗糙表面之间的接触导热模型.与实验数据的对比分析表明:该模型能够正确地反映接触导热现象.在此基础上,对接触表面进行了合理的简化,建立了接触界面间的辐射传热模型.数值计算表明:当接触表面的温度高于400K时,辐射的影响已不可忽略;载荷对接触导热热导的影响明显大于对辐射热导的影响,导热热导随载荷的增大迅速增大,而辐射热导以及等效辐射系数均随载荷的增大有所减小,这主要是由接触界面的空隙面积减少造成的;在接触面几何参数中,粗糙峰等效斜率对等效辐射系数起着主导作用,在相同的量纲1的载荷情况下,粗糙峰等效斜率越小,等效辐射系数越大;通过对本文提出的等效辐射系数的误差检验,结果表明其最大相对误差为10-3数量级,说明等效辐射系数仅仅为接触界面黑度、几何特性和接触载荷的函数,而与接触界面温度水平和温差无关,同时也间接证明了本文提出的等效辐射系数可以较为合理地描述接触界面间的辐射换热强度.
By using the GW statistical contact model, the contact thermal conductivity model between the rough surfaces is established. Comparing with the experimental data, the model shows that the model can correctly reflect the contact thermal conductivity. On this basis, the contact surface is simplified and established The radiation heat transfer model between the contact interfaces is obtained.The numerical results show that the influence of radiation can not be neglected when the contact surface temperature is higher than 400K.The influence of the load on the contact thermal conductivity is significantly greater than that on the radiation thermal conductivity.The thermal conductivity The increasing of the guided load increases rapidly, while the radiative heat conduction and the equivalent radiation coefficient decrease with the increase of the load, which is mainly caused by the decrease of the void area of the contact interface. In the geometrical parameters of the contact surface, The equivalent slope of the roughness peak plays a leading role in the equivalent radiation coefficient. Under the same load of dimension 1, the smaller the equivalent slope of the roughness peak, the larger the equivalent radiation coefficient. By comparing the equivalent emissivity The results show that the maximum relative error is about 10-3, indicating that the equivalent radiation coefficient is only a function of the contact interface blackness, geometric properties and contact load, Level irrespective of the temperature difference and also demonstrated indirectly equivalent emissivity of the paper can be described more reasonable strength between radiation heat transfer contact interface.